Curious about calcium

[Archie73]

Hi does anyone know what happens when horses are fed too much calcium in terms of balance against other minerals?

Just had analysis done and the one thing that jumps out is both grass and hay very high comparatively speaking

Will obviously get pro advice shortly but just very eager.

Thanks!

 

[Natch]

The main thing is it can cause a shortage of phosphorus I think. Excess calcium in the diet is quite well tolerated (and its reasonably common) but prolonged excess can cause kidney stones and calcification of tendons. *I think*... Will dig out my notes if you like. Somewhere I probably still have the relevant pages of the NRC 2007 Equine Nutrition book, if you want the definitive guide.

 

[Oberon]

As well as being important for bones and teeth, calcium is one of the major minerals that;
• Triggers muscle contraction.
• Helps to regulate the heart pacemaker.
• Regulates the excitability of nerves.
• Sets the seizure threshold.
• Relaxes muscle in the walls of blood vessels.
• Is required in muscle as an enzyme cofactor for the breakdown of glycogen from the liver to release as an energy source.
• Is required for normal blood clotting.
• Is required for the transformation of skin to the keratinocytes that form hoof horn.
• Is necessary to form strengthening crosslinks between keratin fibres in the hoof.
Horses (and rabbits) are unique from other mammals in that their absorption of calcium from the diet is very high and Vitamin D is not the sole facilitator in their absorption of calcium in the intestine.
Horses have high amounts of calcium in their urine – which is what gives it the whitish, cloudy appearance.
Calcium is absorbed only in the small intestine and has competition for absorption from Phosphorous and (believed) Magnesium.
Sweat loss of calcium is 212mg per litre.
Horses fed a forage based diet are found to absorb more calcium than those fed a grain and forage diet.
Salt is found to increase absorption of calcium.

Alfalfa is considered the most bioavailable of calcium (but please be aware of your existing calcium levels and phosphorous levels in your forage before feeding alfalfa).
You will see calcium carbonate (limestone flour) supplemented in most commercial feeds and supplements. Often this is to balance the phosphorus in wheat feed/wheat bran which is used as a cheap filler and carrier in laminitis’ marketed feeds.
Calcium carbonate is also used in gastric and ulcer marketed supplements. In humans it is better known as Rennie’s.

 

[Archie73]

Hmmmmmn two very consise answers. Thank you both. My next question would obviously relate to phosphate but I will wait until my hand holding expert has a look at my analysisS thanks again.